The present invention is directed to colorant compounds. More specifically, the present invention is directed to azo pyridone colorant compounds particularly suitable for use in hot melt or phase change inks. One embodiment of the present invention is directed to compounds of the formula 
wherein (A) R3 is a linear alkyl group of the formula xe2x80x94(CH2)cCH3 wherein c is an integer of 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9; (B) Z is (i) a hydrogen atom, (ii) a halogen atom, (iii) a nitro group, (iv) an alkyl group, (v) an aryl group, (vi) an arylalkyl group, (vii) an alkylaryl group, (viii) a group of the formula 
wherein R70 is an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, (ix) a sulfonyl group of the formula xe2x80x94SO2R80 wherein R80 is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, or (x) a phosphoryl group of the formula xe2x80x94PO3R90 wherein R90 is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group; and (C) either (1) X is an oxygen atom, R1 is 
wherein q is an integer of from about 10 to about 15, p is an integer of from 0 to about 3, and the sum of p+q=15, 
or
xe2x80x94(CH2)17CH3 
and R2 is
xe2x80x94CH2CH3,
xe2x80x94(CH2)3CH3,
xe2x80x94(CH2)7CH3,
xe2x80x94(CH2)9CH3,
xe2x80x94(CH2)11CH3,
xe2x80x94(CH2)13CH3,
xe2x80x94(CH2)15CH3,
xe2x80x94(CH2)17CH3, 
wherein z is an integer of from about 34 to about 44, or (2) X is a xe2x80x94NHxe2x80x94 group and (i) R1 is 
wherein q is an integer of from about 10 to about 15, p is an integer of from 0 to about 3, and the sum of p+q=15, 
or
xe2x80x94(CH2)17CH3 
and R2 is
xe2x80x94CH2CH3,
xe2x80x94(CH2)3CH3,
xe2x80x94(CH2)7CH3,
xe2x80x94(CH2)9CH3,
xe2x80x94(CH2)11CH3,
xe2x80x94(CH2)13CH3,
xe2x80x94(CH2)15CH3,
xe2x80x94(CH2)17CH3, 
wherein z is an integer of from about 34 to about 44, or (ii) R1 is 
and R2 is
xe2x80x94CH2CH3, 
xe2x80x94CH2CH2CH2OH, 
wherein z is an integer of from about 34 to about 44.
In general, phase change inks (sometimes referred to as xe2x80x9chot melt inksxe2x80x9d) are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.
Phase change inks for color printing typically comprise a phase change ink carrier composition which is combined with a phase change ink compatible colorant. In a specific embodiment, a series of colored phase change inks can be formed by combining ink carrier compositions with compatible subtractive primary colorants. The subtractive primary colored phase change inks can comprise four component dyes, namely, cyan, magenta, yellow and black, although the inks are not limited to these four colors. These subtractive primary colored inks can be formed by using a single dye or a mixture of dyes. For example, magenta can be obtained by using a mixture of Solvent Red Dyes or a composite black can be obtained by mixing several dyes. U.S. Pat. Nos. 4,889,560, 4,889,761, and 5,372,852, the disclosures of each of which are totally incorporated herein by reference, teach that the subtractive primary colorants employed can comprise dyes from the classes of Color Index (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, and Basic Dyes. The colorants can also include pigments, as disclosed in, for example, U.S. Pat. No. 5,221,335, the disclosure of which is totally incorporated herein by reference. U.S. Pat. No. 5,621,022, the disclosure of which is totally incorporated herein by reference, discloses the use of a specific class of polymeric dyes in phase change ink compositions.
Phase change inks have also been used for applications such as postal marking and industrial marking and labelling.
Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.
Compositions suitable for use as phase change ink carrier compositions are known. Some representative examples of references disclosing such materials include U.S. Pat. Nos. 3,653,932, 4,390,369, 4,484,948, 4,684,956, 4,851,045, 4,889,560, 5,006,170, 5,151,120, 5,372,852, 5,496,879, European Patent Publication 0187352, European Patent Publication 0206286, German Patent Publication DE 4205636AL, German Patent Publication DE 4205713AL, and PCT Patent Application WO 94/04619, the disclosures of each of which are totally incorporated herein by reference. Suitable carrier materials can include paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, fatty acids and other waxy materials, fatty amide containing materials, sulfonamide materials, resinous materials made from different natural sources (tall oil rosins and rosin esters, for example), and many synthetic resins, oligomers, polymers, and copolymers.
European Patent Publication 1 125 990 A1 and PCT Patent Publication WO 01/09256 A1, the disclosures of each of which are totally incorporated herein by reference, discloses an aqueous ink for ink jet recording which contains at least a water-insoluble coloring matter, water, and a resin as main components and which takes the form of an emulsion, which is characterized by containing at least one yellow hue coloring matter selected from the group consisting of a quinophthalone compound represented by the formula (1) 
wherein each of R1 to R3 independently represents a hydrogen atom, an unsubstituted or substituted alkyl group, xe2x80x94CONR4R5, or xe2x80x94COOR6 (in which each of R4 to R6 independently represents a hydrogen atom, an unsubstituted or substituted alkyl group, or an unsubstituted or substituted aryl group) and all of R1 to R3 are not a hydrogen atom at the same time, and a pyridone azo compound represented by the formula (2) 
wherein each of R7 to R11 independently represents a hydrogen atom, a halogen atom, an unsubstituted or substituted alkyl group, an aralkyl group, an unsubstituted or substituted alkoxy group, an unsubstituted or substituted aryl group, an unsubstituted or substituted aryloxy group, a hydroxyl group, xe2x80x94NR14R15 (in which R14 and R15 independently represent a hydrogen atom, an unsubstituted or substituted alkyl group, or an aralkyl group), xe2x80x94COX1 (in which X1 represents an unsubstituted or substituted alkoxy group, an unsubstituted or substituted aryloxy group, or xe2x80x94NR16R17 (in which each of R16 and R17 independently represent a hydrogen atom, an unsubstituted or substituted alkyl group, an aralkyl group, or an unsubstituted or substituted aryl group)), xe2x80x94COO(CH2)nxe2x80x94COX2, xe2x80x94OCOX3, or xe2x80x94NHCOX4 (in which each of X2 to X4 independently represents an unsubstituted or substituted alkyl group, an aralkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted alkoxy group, or an unsubstituted or substituted aryloxy group, and n is an integer of 1 to 3), R12 represents an unsubstituted or substituted alkyl group, and R13 represents an unsubstituted or substituted alkyl group, an aralkyl group, or an unsubstituted or substituted aryl group. The ink is for ink jet recording having excellent light resistance and storage stability, and enables formation of a high quality image without blotting, and the obtained recording image is excellent in water resistance.
PCT Patent Publication WO 01/21714, the disclosure of which is totally incorporated herein by reference, discloses compositions comprising a solvent and at least one compound of the formula 
in which R1 represents H, an optionally substituted C1-8 carbyl derived group, or a group of the formula 
where C is from 2 to 6, R3 represents optionally substituted C1-8 carbyl derived group, R4 and R5 independently represent an optional substituent, R2 represents an optionally substituted C1-8 carbyl derived group, X Y, and Z independently represent H or an optional substituent, M represents H or a cation, and m and n independently represent 0, 1, or 2. Also disclosed are compounds of the above formula providing that at least one of R1, R2, X, Y, or Z comprises a group of formula SO3M or PO3M2. These compositions and compounds are useful as the colorants to prepare color filters for displays.
U.S. Pat. No. 4,247,456 (von Brachel et al.), the disclosure of which is totally incorporated herein by reference, discloses water-insoluble monoazo dyes of the formula 
wherein R is the residue of a benzene, naphthalene, diphenyl, diphenylmethane, or heterocyclic diazo compound which is free from water solubilizing groups, produced by reacting a diazotized amine of the benzene, naphthalene, diphenyl, diphenylmethane, or heterocyclic series which is free from water solubilizing groups with the appropriate 6-hydroxy-2-pyridone and the utility thereof for the dyeing and printing of synthetic fabric materials to yellow to red shades having excellent fastness to light and sublimation.
U.S. Pat. No. 3,957,749 (von Brachel et al.), the disclosure of which is totally incorporated herein by reference, discloses water-insoluble monoazo dyes of the formula 
produced by reacting a diazotized amine of the benzene, naphthalene, diphenyl, diphenylmethane, or heterocyclic series which is free from water solubilizing groups with the appropriate 6-hydroxy-2-pyridone and the utility thereof for the dyeing and printing of synthetic fabric materials to yellow to red shades having excellent fastness to light and sublimation.
Japanese Patent Publication JP 05331382, the disclosure of which is totally incorporated herein by reference, discloses a specific pyridone azo pigment which is bright yellow and highly soluble in a solvent, absorbs light of long wavelength, and is useful for a thermal transfer sheet. The pyridone azo pigment is represented by the formula 
wherein R is H, alkyl, substituted alkyl, cycloalkyl, aryl, or optionally substituted phenyl, and ring A is a benzene ring optionally having a nonionic group. The pigment is prepared by diazotizing an aniline compound and coupling the resulting diazo compound with a pyridone compound. Having a good solubility in an organic solvent and a good dispersibility in water, the pigment facilitates the preparation of an ink containing a high concentration of the pigment homogeneously dissolved or dispersed. The prepared ink enables the preparation of a thermal transfer sheet coated with the ink uniformly in a high density.
British Patent 1,559,001 (Harvey et al.), the disclosure of which is totally incorporated herein by reference, discloses a hydrophilic textile material colored with a dyestuff of the formula 
wherein D is the residue of a diazo or tetrazo component; R1 is a hydrogen atom or an alkyl, chloro, acetamido, benzamido, carbamoyl, or an N-substituted carbamyl, for example xe2x80x94CONHBr, group or, preferably, a cyano group; R2 is an alkyl group, especially methyl, optionally substituted with a chlorine atom, a phenyl group, optionally substituted with an alkyl or alkoxy group, or a carboxylic acid or carboxylic acid ester group; or R1 and R2 together with the carbon atoms in the 3- or 4-position of the pyridone ring may form an alicyclic or aromatic ring system so that, for example, R1 and R2 together may be a tri- or tetra-methylene group forming with the pyridone of penteno [c] or hexeno [c] pyrid-2-one, or R1 and R2 may form together with the adjacent carbon atoms of the pyridone ring a benzene ring giving a benz [c] pyrid-2one; R3 is an aryl group carrying one or more substituents selected from xe2x80x94NO, xe2x80x94SO2R1, xe2x80x94COR1, xe2x80x94COOR1, xe2x80x94CF, or xe2x80x94CN, wherein R1 is an optionally substituted alkyl or aryl group; and n is an integer which may be 1 or 2.
German Patent Publication DE 19646430, the disclosure of which is totally incorporated herein by reference, discloses dye mixtures comprising at least two structurally different dyes, each corresponding to formula 
wherein R1 is C1-C4 alkyl; R2 is the (CH2)nOxe2x80x94R5 radical; R5 is, independently of R1, C1-C4 alkyl or phenyl (which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxy, or halogen); and n is 2 or 3, which dye mixtures are suitable for dyeing or printing textile fibre materials (e.g. polyester materials), giving dyeings having good around fastness properties.
German Patent Publication DE 19646429, the disclosure of which is totally incorporated herein by reference, discloses dye mixtures comprising at least two structurally different dyes, each of which has the formula 
in which R1 is C1-C4 alkyl and R2 is isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl; or C1-C3 alkyl which is substituted by phenyl or phenoxy; or R1 is phenyl (which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, or halogen), C1-C4 alkoxy-C1-C3 alkylene, phenoxy-C1-C3 alkylene, or C1-C3 alkyl which is substituted by phenyl (which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, or halogen) and R2 is C1-C10 alkyl (which is unsubstituted or substituted by hydroxyl, OCOR3, or phenoxy, where the phenyl ring in phenoxy is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, or halogen) and the alkyl chain in C1-C10 alkyl from C2 can be interrupted by one or more oxygen atoms; phenyl (which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, or halogen); or C5-C7 cycloalkyl; and R3 is C1-C4 alkyl, are suitable for dyeing or printing textile fibre materials (e.g. polyester materials) and give dyeings with good allround properties.
German Patent Publication DE 19647869, the disclosure of which is totally incorporated herein by reference, discloses a dye mixture containing at least 2 dyes with different structures, each of formula 
where R1 is a 1-4C alkyl; and R2 is a linear 1-3C alkyl. Also claimed is hydrophobic fibre material, preferably polyester textile material, dyed or printed with the mixture.
PCT Patent Publication WO 99/43754, the disclosure of which is totally incorporated herein by reference, discloses compounds of the formula 
and salts and tautomers thereof, wherein: R1 and R2 each independently is H, optionally substituted alkyl, optionally substituted aryl, or optionally substituted arylalkyl; each W and each X independently is xe2x80x94COOH, xe2x80x94SO3H, xe2x80x94PO3H2, or alkyl substituted by one or more groups selected from xe2x80x94COOH, xe2x80x94SO3H, and xe2x80x94PO3H2; each Y and each Z independently is a substituent other than those defined for W and X; a and d each independently is 1 to 5; b and c each independently is 0 to 4; (a+b) has a value of 5 or less; and (c+d) has a value of 5 or less. Also claimed are inks containing a compound of this formula, an ink jet printing process using the inks, substrates printed with the inks, and ink jet printer cartridges containing the inks.
U.S. Pat. No. 5,929,218 (Lee et al.), the disclosure of which is totally incorporated herein by reference, discloses pyridone-based yellow monoazo dyes used in thermal transfer having following formula which have good stability and hue 
wherein R1 is hydrogen atom; unsubstituted or substituted alkyl group of from 1 to 8 carbon atoms with alkoxy or aryl; or unsubstituted or substituted aryl group with alkoxy or halogen, and X is hydrogen atom; alkyl group of from 1 to 4 carbon atoms; alkoxy group; or halogen; R2 is selected from the following groups; 
wherein R3 and R4 are independently selected from groups consisting hydrogen, substituted or unsubstituted alkyl group of from 1 to 4 carbon atoms, halogen, alkyl carboxylate, and carbonyl group; R3-R4 is noncyclization with R3 and R4 and selected respectively from the above substituents (R3 and R4); or saturated or unsaturated cycloalkyl of from 3 to 6 carbon atoms, Z is nitro, halogen, alkyl group of from 1 to 4 carbon atoms, alkoxy, sulfonyl, carbonyl, carboxyamide, sulfonamino, cyano, hydroxy, or hydrogen atom.
European Patent Publication EP 0 706 679 B1, U.S. Pat. No. 5,853,929 (Campbell), and PCT Patent Publication WO 95/00885, the disclosures of each of which are totally incorporated herein by reference, disclose colored cyan toner for electroreprography and laser printing based on Solvent Blue 70, and a trichomatic set of coloured toners based on Solvent Blue 70, benzodifuranone red dyes, and azo pyridone yellow dyes of the formula 
wherein X is halogen, nitro, or a group xe2x80x94COOR5, R9 is C1-4 alkyl, R10 is C1-12 alkyl, R5 is C1-8 alkyl or a group of formula xe2x80x94(C1-3-alkylene)xe2x80x94(CO)qxe2x80x94Z wherein q is 0 or 1 and Z is xe2x80x94OR6 or xe2x80x94NR6R7 when q=1 or Z is xe2x80x94OR8 when q=0, R6 is selected from optionally substituted C1-8 alkyl, optionally substituted C1-8 alkoxy-C1-8 alkyl, and a second group represented by R5 in which R6 is optionally substituted C1-8 alkyl or optionally substituted C1-8 alkoxy-C1-8 alkyl, R7 is selected from H and optionally substituted C1-8 alkyl, and R8 is selected from optionally substituted C1-8 alkyl, optionally substituted C1-8 alkoxy-C1-8 alkyl, optionally substituted C1-8 alkyl sulfonyl or carbonyl, and optionally substituted phenyl sulfonyl or carbamoyl.
European Patent Publication EP 0 247 737, the disclosure of which is totally incorporated herein by reference, discloses a thermal transfer printing sheet suitable for use in a thermal transfer printing process, especially for the conversion of a digital image into a visible print, comprising a substrate having a coating comprising a dye of the formula 
wherein Ring A is unsubstituted or carries, in the 2- or 4-position with respect to the azo link, at least one group selected from xe2x80x94CX3, X1, CN, NO2, xe2x80x94OCO.Y, xe2x80x94CO.Y, xe2x80x94CO.H, xe2x80x94OSO2.Y, and xe2x80x94SO2.Y, provided that A is substituted when Z is CH3 and R is C2-4-alkyl; X and X1 are each independently halogen; Y is selected from R1, xe2x80x94OR1, SR1, and xe2x80x94NR1R2; R1 is selected from C1-12-alkyl, C1-12-alkyl interrupted by one or two groups selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, O.COxe2x80x94, and xe2x80x94CO.Oxe2x80x94, C3-7-cycloalkyl, mono- or bi-cyclic aryl, and C1-3-alkylene attached to an adjacent carbon atom on Ring A; R2 is selected from H, C1-12-alkyl, C3-7-cycloalkyl, and mono- or bi-cyclic aryl; Z is C1-12-alkyl or phenyl; and R is selected from C2-12-alkyl unbranched in the alpha-position, C2-12-alkyl unbranched in alpha-position and interrupted by one or two groups selected from xe2x80x94Oxe2x80x94,xe2x80x94COxe2x80x94, O.COxe2x80x94, and xe2x80x94CO.Oxe2x80x94, phenyl, C1-4-alkylphenyl, biphenyl, and biphenyl interrupted by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, O.COxe2x80x94, and xe2x80x94CO.Oxe2x80x94, each of which is free from hydrogen atoms capable of intermolecular hydrogen bonding.
U.S. Pat. No. 5,041,413 (Evans et al.), the disclosure of which is totally incorporated herein by reference, discloses a yellow dye-donor element for thermal dye transfer comprises a support having thereon a dye layer comprising a mixture of yellow dyes dispersed in a polymeric binder, at least one of the yellow dyes having the formula 
wherein: each R1 independently represents a substituted or unsubstituted alkyl group of from 1 to about 10 carbon atoms, a cycloalkyl group of from about 5 to about 7 carbon atoms; a substituted or unsubstituted allyl group; an aryl group of from about 6 to about 10 carbon atoms; a hetaryl group of from 5 to 10 atoms; acyl; arylsulfonyl; aminocarbonyl; aminosulfonyl; fluorosulfonyl; halogen; nitro; alkylthio; or arylthio; or any two adjacent R1""s together represent the atoms necessary to form a 5- or 6-membered fused ring; n represents an integer from 0-4; R2 represents hydrogen; a substituted or unsubstituted alkyl, cycloalkyl, allyl, aryl or hetaryl group as described above for R1; cyano; acyl; alkylsulfonyl; arylsulfonyl; or alkoxycarbonyl; Z represents cyano; alkoxycarbonyl; acyl; nitro; arylsulfonyl or alkylsulfonyl; Y represents hydrogen; a substituted or unsubstituted alkyl, cycloalkyl, allyl, aryl or hetaryl group as described above for R1; amino; alkylamino; arylamino; acylamino; or sulfonylamino; and at least one of the other of the dyes having the formula 
wherein R3 represents the same groups as R1 above; R4 and R5 each independently represents hydrogen, R3; cyano; acyloxy; alkoxy of 1 to about 6 carbon atoms; halogen; or alkoxycarbonyl; or any two of R3, R4 and R5 together represent the atoms necessary to complete a 5- to 7-membered ring; R6 represents the same groups as R3; G represents a substituted or unsubstituted alkyl, cycloalkyl or allyl group as described above for R3, NR7R8 or OR9; R7 and R8 each independently represents hydrogen, acyl or R3, with the proviso that R7 and R8 cannot both be hydrogen at the same time; or R7 and R8 together represent the atoms necessary to complete a 5- to 7-membered ring; R9 represents the same groups as R3; X represents C(R10)(R11), S, O or NR10; R10 and R11 each independently represents the same groups as R3; or R10 and R11 together represent the atoms necessary to complete a 5- to 7-membered ring; and J represents the atoms necessary to complete a 5- or 6-membered ring which may be fused to another ring system.
U.S. Pat. No. 4,359,418 (Lienhard et al.), the disclosure of which is totally incorporated herein by reference, discloses azo dyestuff sulfonic acid salts of the formula 
wherein A represents a carbocyclic or heterocyclic aromatic radical, B represents an aliphatic, cycloaliphatic or araliphatic amine, X represents a hydrogen atom or a substituted or unsubstituted alkyl group, a cycloalkyl, aralkyl or aryl group, Y represents a hydrogen or halogen atom, a nitro, cyano, acyl, sulfonic acid, arylsulfonyl, alkoxycarbonyl group or a substituted or unsubstituted alkyl, sulfamoyl or carbamoyl group, Z represents a substituted or unsubstituted alkyl group or an aryl radical, m and n are 1 or 2; said dyestuffs salts having good solubility in organic solvents and functioning to color solutions of film forming polymers in yellow to orange shades.
German Patent Publication DE 3538517 and U.S. Pat. No. 5,037,964 (Moser et al.), the disclosures of each of which are totally incorporated herein by reference, disclose sulfonic acid group-free basic azo compounds, which correspond in one of the possible Lautomeric forms to the formula 
their preparation and their use for dyeing paper.
Japanese Patent Publication JP 03192158, the disclosure of which is totally incorporated herein by reference, discloses obtaining a yellow dye exhibiting high dyeing speed and degree of exhaustion in dyeing a textile material, leather, pulp, paper, etc., as well as excellent brightness and fastness to water by selecting a compound wherein a pyridopyridinium salt is linked to diphenylfluorene through azo groups. A cationic compound of the formula 
wherein R1 is H or 1-4C alkyl; R2 is H, 1-4C alkyl, or alkoxy; and Axe2x88x92 is an anion which has a structure wherein a tetrazo compound, of 9,9xe2x80x2-bis(4-anilino)fluorene is coupled with a pyridone derivative is selected as a yellow dye, which is useful for dyeing an unsized pulp or paper (e.g. a napkin, table cloth, or sanitary paper). The dyeing with the dye is carried out at a pH of 4-8, preferably 5-7, and at 10-50xc2x0 C., preferably 15-30xc2x0 C.
British Patent Publication GB 2 008 606, the disclosure of which is totally incorporated herein by reference, discloses water-insoluble yellow monoazo dyes suitable for dyeing hydrophobic synthetic fibres, particularly polyesters, having the formula 
in which X represents OR3 or NHR3, NR3R4 (R3, R4 together optionally forming with N a ring having 5 to 6 carbon atoms, NHR5; R1 represents a hydrogen atom, an alkyl having 1 to 5 carbon atoms, (CH2)2OH or (CH2)3OR3; R2 represents CN, COOR3, CONHR3, CONR3R4 (R3, R4 together optionally forming with N a ring having 5 to 6 carbon atoms); R3 and R4 represent alkyl groups having 1 to 5 carbon atoms; and R5 represents a cycloalkyl having 5 or 6 carbon atoms. The dyes may be prepared by the reaction of 
with Hal-CH2xe2x80x94COxe2x80x94X in which Hal represents Cl or Br.
xe2x80x9cPreparation and Evaluation of Yellow Pigments Based on H-Pyridone and Esters of Aminoterephthalic Acid,xe2x80x9d P. Slosar et al., CHEMagazin, Vol. 9, No. 6, pp. 8-11 (1999), the disclosure of which is totally incorporated herein by reference, discloses yellow pigments based on H-pyridone and esters of aminoterephthalic acid wherein the color strength, brilliance (purity), and deepening of greenish shade were the larger the smaller alkyl is in the carbalkoxy group in o-position towards the azo group and the greater alkyl is in the carbalkoxy group in m-position towards the azo group.
Of potential background interest with respect to the present invention are the following references: U.S. Pat. Nos. 5,919,839; 5,827,918; 4,889,560; 5,372,852; xe2x80x9cSynthesis, Morphology, and Optical Properties of Tetrahedral Oligo(phenylenevinylene) Materials,xe2x80x9d S. Wang et al., J. Am. Chem. Soc., Vol. 120, p. 5695 (2000); xe2x80x9cSyntheses of Amphiphilic Diblock Copolymers Containing a Conjugated Block and Their Self-Assembling Properties,xe2x80x9d H. Wang et al., J. Am. Chem. Soc., Vol. 122, p. 6855 (2000); xe2x80x9cCrystal Engineering of Conjugated Oligomers and the Spectral Signature of xcfx80 Stacking in Conjugated Oligomers and Polymers,xe2x80x9d A. Koren et al., Chem. Mater., Vol. 12, p. 1519 (2000); xe2x80x9cThe Chemistry of Isatoic Anhydride,xe2x80x9d G. M. Coppola, Synthesis, p. 505 (1980); xe2x80x9cIsatoic Anhydride. IV. Reactions with Various Nucleophiles,xe2x80x9d R. P. Staiger et al., J. Org. Chem., Vol. 24, p. 1214 (1959); xe2x80x9cInvestigation of the Reaction Conditions for the Synthesis of 4,6-Disubstituted-3-cyano-2-pyridones and 4-Methyl-3-cyano-6-hydroxy-2-pyridone,xe2x80x9d D. Z. Mijin et al., J. Serb. Chem. Soc., Vol. 59, No. 12, p. 959 (1994); xe2x80x9cSynthesis of Isoquinoline Alkaloids. II. The Synthesis and Reactions of 4-Methyl-3-pyridinecarboxaldehyde and Other 4-Methyl-3-substituted Pyridines, J. M. Bobbitt et al., J. Org. Chem., Vol 25, p. 560 (1960); xe2x80x9cSynthesis and Dyeing Characteristics of 5-(4-Arylazophenyl) azo-3-cyano-4-methyl-6-hydroxy-2-pyridones,xe2x80x9d J. Kanhere et al., Indian Journal of Textile Research, Vol. 13, p. 213 (1988); xe2x80x9cSynthesis of Some Pyridone Azo Dyes from 1-Substituted 2-Hydroxy-6-pyridone Derivatives and their Colour Assessment,xe2x80x9d C. Chen et al., Dyes and Pigments, Vol. 15, p. 69 (1991); German Patent Publication DE 3543360; Japanese Patent Publication JP 2001214083; German Patent Publication DE 3505899; Indian Patent Publication 147527; European Patent Publication EP 0 524 637; European Patent Publication EP 0 529 282; European Patent Publication EP 0 083 553; Japanese Patent Publication JP 2000 62327; Japanese Patent Publication JP 85152563; xe2x80x9cSynthesis of 3-Cyano-6-hydroxy-5-(2-(perfluoroalkyl)phenylazo)-2-pyridones and their Application for Dye Diffusion Thermal Transfer Printing,xe2x80x9d Bull. Chem. Soc. Jpn., 1993, Vol. 66, Iss. 6, Pp.1790-4; European Patent Publication 0844287; European Patent Publication 0 404 493; U.S. Pat. Nos. 5,902,841; 5,621,022; 5,006,170; Chinese Patent Publication CN 1115773; German Patent Publication DE 3447117; Japanese Patent Publication JP 5331382; Japanese Patent Publication JP 63210169; Japanese Patent Publication JP 63199764; Japanese Patent Publication JP 63199763; Japanese Patent Publication JP 63199762; Japanese Patent Publication JP 63199761; Japanese Patent Publication JP 63199760; Japanese Patent Publication JP 63071392; Japanese Patent Publication JP 61181865; Japanese Patent Publication JP 61036366; Japanese Patent Publication JP 60152563; Japanese Patent Publication JP 60112862; Japanese Patent Publication JP 60112861; Japanese Patent Publication JP 58149953; Japanese Patent Publication JP 56092961; Japanese Patent Publication JP 56026957; Japanese Patent Publication JP 55099958; Japanese Patent Publication JP 96 11443 (JP8011443); Japanese Patent Publication JP 93169849 (JP5169849); Japanese Patent Publication JP 93 51536 (JP5051536); Japanese Patent Publication JP 90185569 (JP2185569); European Patent Publication 0 319 234; European Patent Publication 0 314 002; European Patent Publication 0 302 401; U.S. Pat. No. 4,734,349; Japanese Patent Publication JP 87290762 (JP62290762); Japanese Patent Publication JP 86244595 (JP61244595); Indian Patent Publication IN 147868; Spanish Patent Publication 475254 (Equivalent of Italian Patent Publication IT 1088895); German Patent Publication DE 2727809; xe2x80x9cColour and Constitution of Azo Dyes Derived from 2-Thioalkyl-4,6-Diaminopyrimidines and 3-Cyano-1,4-dimethyl-6-hydroxy-2-pyridone as Coupling Components,xe2x80x9d L. Cheng et al., Dyes and Pigments, Vol. 7, No. 5, pp. 373-388 (1986); European Patent Publication 1 168 046; U.S. Pat. No. 4,644,058: Japanese Patent Publication JP 63039380; Japanese Patent Publication JP 54102328; Japanese Patent Publication JP 54070337; xe2x80x9cTrends in Modern Dye Chemistry. Part 10,xe2x80x9d N. R. Ayyangar and K. V. Srinivasan, Colourage, Vol. 37, No. 2, pp. 29-30 (Jan. 16, 1990); European Patent Publication EP 0 172 283; Japanese Patent Publication JP 05169854; Japanese Patent Publication JP 04292988; Japanese Patent Publication JP 63161060; Japanese Patent Publication JP 61244595; Korean Patent Publication KR 119563; European Patent Publication EP 0 142 863; European Patent Publication EP 0 023 770; Japanese Patent Publication JP 00239549 (JP2000239549); Japanese Patent Publication JP 11269402; Japanese Patent Publication JP 09041267; Japanese Patent Publication JP 08039941; U.S. Pat. No. 4,994,564; Japanese Patent Publication JP 06294909; Japanese Patent Publication JP 06122829; Japanese Patent Publication JP 05255602; Japanese Patent Publication JP 05051536; Japanese Patent Publication JP 04235093; European Patent Publication EP 0 468 647; European Patent Publication EP 0 063 275; U.S. Pat. No. 4,216,145; and German Patent Publication DE 2606506; the disclosures of each of which are totally incorporated herein by reference.
While known compositions and processes are suitable for their intended purposes, a need remains for new yellow colorant compositions. In addition, a need remains for yellow colorant compositions particularly suitable for use in phase change inks. Further, a need remains for yellow colorants with desirable thermal stability. Additionally, a need remains for yellow colorants that exhibit minimal undesirable discoloration when exposed to elevated temperatures. There is also a need for yellow colorants that exhibit a desirable brilliance. In addition, there is a need for yellow colorants that exhibit a desirable hue. Further, there is a need for yellow colorants that are of desirable chroma. Additionally, there is a need for yellow colorants that have desirably high lightfastness characteristics. A need also remains for yellow colorants that have a desirably pleasing color. In addition, a need remains for yellow colorants that exhibit desirable solubility characteristics in phase change ink carrier compositions. Further, a need remains for yellow colorants that enable phase change inks to be jetted at temperatures of over 135xc2x0 C. while maintaining thermal stability. Additionally, a need remains for yellow colorants that enable phase change inks that generate images with low pile height. There is also a need for yellow colorants that enable phase change inks that generate images that approach lithographic thin image quality. In addition, there is a need for yellow colorants that exhibit oxidative stability. Further, there is a need for yellow colorants that do not precipitate from phase change ink carriers. Additionally, there is a need for yellow colorants that do not, when included in phase change inks, diffuse into adjacently printed inks of different colors. A need also remains for yellow colorants that do not leach from media such as phase change ink carriers into tape adhesives, paper, or the like. In addition, a need remains for yellow colorants that, when incorporated into phase change inks, do not lead to clogging of a phase change ink jet printhead. Further, there is a need for yellow colorants that enable phase change inks that generate images with sharp edges that remain sharp over time. Additionally, there is a need for yellow colorants that enable phase change inks that generate images which retain their high image quality in warm climates. Further, there is a need for yellow colorants that enable phase change inks that generate images of desirably high optical density. Additionally, there is a need for yellow colorants that, because of their good solubility in phase change ink carriers, enable the generation of images of low pile height without the loss of desirably high optical density. A need also remains for yellow colorants that enable cost-effective inks.
The present invention is directed to compounds of the formula 
wherein (A) R3 is a linear alkyl group of the formula xe2x80x94(CH2)cCH3 wherein c is an integer of 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9; (B) Z is (i) a hydrogen atom, (ii) a halogen atom, (iii) a nitro group, (iv) an alkyl group, (v) an aryl group, (vi) an arylalkyl group, (vii) an alkylaryl group, (viii) a group of the formula 
wherein R70 is an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, (ix) a sulfonyl group of the formula xe2x80x94SO2R80 wherein R80 is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group, or (x) a phosphoryl group of the formula xe2x80x94PO3R90 wherein R90 is a hydrogen atom, an alkyl group, an aryl group, an arylalkyl group, an alkylaryl group, an alkoxy group, an aryloxy group, an arylalkyloxy group, an alkylaryloxy group, a polyalkyleneoxy group, a polyaryleneoxy group, a polyarylalkyleneoxy group, a polyalkylaryleneoxy group, a heterocyclic group, a silyl group, a siloxane group, a polysilylene group, or a polysiloxane group; and (C) either (1) X is an oxygen atom, R1 is 
wherein q is an integer of from about 10 to about 15, p is an integer of from 0 to about 3, and the sum of p+q=15, 
or
xe2x80x94(CH2)17CH3 
and R2 is
xe2x80x94CH2CH3,
xe2x80x94(CH2)3CH3,
xe2x80x94(CH2)7CH3,
xe2x80x94(CH2)9CH3,
xe2x80x94(CH2)11CH3,
xe2x80x94(CH2)13CH3,
xe2x80x94(CH2)15CH3,
xe2x80x94(CH2)17CH3, 
wherein z is an integer of from about 34 to about 44, or (2) X is a xe2x80x94NHxe2x80x94 group and (i) R1 is 
wherein q is an integer of from about 10 to about 15, p is an integer of from 0 to about 3, and the sum of p+q=15, 
or
xe2x80x94(CH2)17CH3 
and R2 is
xe2x80x94CH2CH3,
xe2x80x94(CH2)3CH3,
xe2x80x94(CH2)7CH3,
xe2x80x94(CH2)9CH3,
xe2x80x94(CH2)11CH3,
xe2x80x94(CH2)13CH3,
xe2x80x94(CH2)15CH3,
xe2x80x94(CH2)17CH3, 
wherein z is an integer of from about 34 to about 44, or (ii) R1 is 
and R2 is
xe2x80x94CH2CH3, 
wherein z is an integer of from about 34 to about 44.
The present invention is directed to colorant compounds of the formula 
Examples of R1 groups include menthyl, of the formula 
wherein the xe2x80x9cSxe2x80x9d indicates that the ring is saturated as opposed to being aromatic, branched saturated hydrocarbon groups containing 18 carbon atoms, of the general formula 
wherein q is an integer of from about 10 to about 15, p is an integer of from 0 to about 3, and the sum of p+q=15, such as isostearyl, oleyl, of the formula 
2-octyldodecyl, of the formula 
cholesteryl, of the formula 
abietyl, including groups of the formula 
as well as hydrogenated and dehydrogenated isomers of the above formula that are also derivatives of the rosin-derived natural product abietic acid, such as didehydroabietyl and the like, 2-ethylhexyl, of the formula 
(1-oxypropyl)-2-octyldodecane, of the formula 
2-(octadecyl)-octadecane, of the formula 
stearyl, of the formula xe2x80x94(CH2)17CH3, and the like.
Examples of R2 groups include ethyl, of the formula xe2x80x94CH2CH3, n-butyl, of the formula xe2x80x94(CH2)3CH3, n-octyl, of the formula xe2x80x94(CH2)7CH3, n-decyl, of the formula xe2x80x94(CH2)9CH3, n-dodecyl, of the formula xe2x80x94(CH2)11CH3, n-tetradecyl, of the formula xe2x80x94(CH2)13CH3, cetyl, of the formula xe2x80x94(CH2)15CH3, stearyl, of the formula xe2x80x94(CH2)17CH3, 2-ethylhexyl, of the formula 
abietyl, including groups of the formula 
as well as hydrogenated and dehydrogenated isomers of the above formula that are also derivatives of the rosin-derived natural product abietic acid, such as didehydroabietyl and the like, 3-propyl octadecanoyl, of the formula 
2,2-dimethyl-1,3-dioxolane-4-methylene, of the formula 
3-hydroxypropyl, of the formula
xe2x80x94CH2CH2CH2OH,
branched alkyl ethers such as those derived from Guerbet alcohols, such as those of the formula 
ester groups having long alkyl chains thereon, such as those of the formula 
wherein z is an integer of from about 34 to about 44, and the like.
R3 is a linear alkyl group of the formula xe2x80x94(CH2)cCH3 wherein c is an integer of 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9, and the like.
X is an oxygen atom or a group of the formula xe2x80x94NHxe2x80x94.
Z is (i) a hydrogen atom, (ii) a halogen atom, including fluorine, chlorine, bromine, and iodine, (iii) a nitro group, (iv) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl group), typically with from 1 to about 50 carbon atoms, preferably with from about 1 to about 20 carbon atoms, and more preferably with from about 1 to about 10 carbon atoms, although the number of carbon atoms can be outside of these ranges, (v) an aryl group (including substituted aryl groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 14 carbon atoms, and more preferably with from about 6 to about 10 carbon atoms, although the number of carbon atoms can be outside of these ranges, (vi) an arylalkyl group (including substituted arylalkyl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, (vii) an alkylaryl group (including substituted alkylaryl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, (viii) a group of the formula 
wherein R70 is an alkyl group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl group), typically with from 1 to about 50 carbon atoms, preferably with from about 1 to about 20 carbon atoms, and more preferably with from about 1 to about 10 carbon atoms, although the number of carbon atoms can be outside of these ranges, an aryl group (including substituted aryl groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 20 carbon atoms, and more preferably with from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, an arylalkyl group (including substituted arylalkyl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkylaryl group (including substituted alkylaryl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkoxy group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkoxy groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl portion of the alkoxy group), typically with from about 1 to about 50 carbon atoms, preferably with from about 4 to about 20 carbon atoms, and more preferably with from about 8 to about 12 carbon atoms, although the number of carbon atoms can be outside of these ranges, an aryloxy group (including substituted aryloxy groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 20 carbon atoms, and more preferably with from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, an arylalkyloxy group (including substituted arylalkyloxy groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkylaryloxy group (including substituted alkylaryloxy groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, a polyalkyleneoxy group, wherein the alkyl portion of the repeat alkyleneoxy groups typically has from about 1 to about 12 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polyethyleneoxy group, a polypropyleneoxy group, a polybutyleneoxy group, or the like, and wherein the number of repeat alkyleneoxy groups typically is from about 2 to about 50 repeat alkyleneoxy groups, although the number of repeat units can be outside of these ranges, a polyaryleneoxy group, wherein the aryl portion of the repeat aryleneoxy groups typically has from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polyphenyleneoxy group, a polynaphthaleneoxy group, a polyphenanthreneoxy group, or the like, and wherein the number of repeat aryleneoxy groups typically is from about 2 to about 20 repeat aryleneoxy groups, although the number of repeat units can be outside of these ranges, a polyarylalkyleneoxy group, wherein the arylalkyl portion of the repeat arylalkyleneoxy groups typically has from about 7 to about 50 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polybenzyleneoxy group, a polyphenylethyleneoxy group, or the like, and wherein the number of repeat arylalkyleneoxy groups typically is from about 2 to about 20 repeat arylalkyleneoxy groups, although the number of repeat units can be outside of these ranges, a polyalkylaryleneoxy group, wherein the alkylaryl portion of the repeat alkylaryleneoxy groups typically has from about 7 to about 50 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polytolueneoxy group or the like, and wherein the number of repeat alkylaryleneoxy groups typically is from about 2 to about 20 repeat alkylaryleneoxy groups, although the number of repeat units can be outside of these ranges, a heterocyclic group (including unsubstituted and substituted heterocyclic groups), typically with from about 2 to about 12 carbon atoms, and typically with from about 4 to about 18 ring atoms, although the number of carbon atoms and the number of ring atoms can be outside of these ranges, wherein the heteroatoms in the heterocyclic groups can be (but are not limited to) nitrogen, oxygen, sulfur, silicon, phosphorus, and the like, as well as mixtures thereof, a silyl group (including unsubstituted and substituted silyl groups), a siloxane group (including unsubstituted and substituted siloxane groups), a polysilylene group (including unsubstituted and substituted polysilylene groups), typically with from 2 to about 100 repeat silylene units, or a polysiloxane group (including unsubstituted and substituted polysiloxane groups), typically with from 2 to about 200 repeat siloxane units, although the number of repeat siloxane units can be outside of this range, (ix) a sulfonyl group of the formula xe2x80x94SO2R80, wherein R80 is a hydrogen atom, an alkyl group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl group), typically with from 1 to about 50 carbon atoms, preferably with from about 1 to about 20 carbon atoms, and more preferably with from about 1 to about 10 carbon atoms, although the number of carbon atoms can be outside of these ranges, an aryl group (including substituted aryl groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 20 carbon atoms, and more preferably with from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, an arylalkyl group (including substituted arylalkyl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkylaryl group (including substituted alkylaryl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkoxy group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkoxy groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl portion of the alkoxy group), typically with from about 1 to about 50 carbon atoms, preferably with from about 4 to about 20 carbon atoms, and more preferably with from about 8 to about 12 carbon atoms, although the number of carbon atoms can be outside of these ranges, an aryloxy group (including substituted aryloxy groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 20 carbon atoms, and more preferably with from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, an arylalkyloxy group (including substituted arylalkyloxy groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkylaryloxy group (including substituted alkylaryloxy groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, a polyalkyleneoxy group, wherein the alkyl portion of the repeat alkyleneoxy groups typically has from about 1 to about 12 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polyethyleneoxy group, a polypropyleneoxy group, a polybutyleneoxy group, or the like, and wherein the number of repeat alkyleneoxy groups typically is from about 2 to about 50 repeat alkyleneoxy groups, although the number of repeat units can be outside of these ranges, a polyaryleneoxy group, wherein the aryl portion of the repeat aryleneoxy groups typically has from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polyphenyleneoxy group, a polynaphthaleneoxy group, a polyphenanthreneoxy group, or the like, and wherein the number of repeat aryleneoxy groups typically is from about 2 to about 20 repeat aryleneoxy groups, although the number of repeat units can be outside of these ranges, a polyarylalkyleneoxy group, wherein the arylalkyl portion of the repeat arylalkyleneoxy groups typically has from about 7 to about 50 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polybenzyleneoxy group, a polyphenylethyleneoxy group, or the like, and wherein the number of repeat arylalkyleneoxy groups typically is from about 2 to about 20 repeat arylalkyleneoxy groups, although the number of repeat units can be outside of these ranges, a polyalkylaryleneoxy group, wherein the alkylaryl portion of the repeat alkylaryleneoxy groups typically has from about 7 to about 50 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polytolueneoxy group or the like, and wherein the number of repeat alkylaryleneoxy groups typically is from about 2 to about 20 repeat alkylaryleneoxy groups, although the number of repeat units can be outside of these ranges, a heterocyclic group (including unsubstituted and substituted heterocyclic groups), typically with from about 2 to about 12 carbon atoms, and typically with from about 4 to about 18 ring atoms, although the number of carbon atoms and the number of ring atoms can be outside of these ranges, wherein the heteroatoms in the heterocyclic groups can be (but are not limited to) nitrogen, oxygen, sulfur, silicon, phosphorus, and the like, as well as mixtures thereof, a silyl group (including unsubstituted and substituted silyl groups), a siloxane group (including unsubstituted and substituted siloxane groups), a polysilylene group (including unsubstituted and substituted polysilylene groups), typically with from 2 to about 100 repeat silylene units, or a polysiloxane group (including unsubstituted and substituted polysiloxane groups), typically with from 2 to about 200 repeat siloxane units, although the number of repeat siloxane units can be outside of this range, or (x) a phosphoryl group of the formula xe2x80x94PO3R90, wherein R90 is a hydrogen atom, an alkyl group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl group), typically with from 1 to about 50 carbon atoms, preferably with from about 1 to about 20 carbon atoms, and more preferably with from about 1 to about 10 carbon atoms, although the number of carbon atoms can be outside of these ranges, an aryl group (including substituted aryl groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 20 carbon atoms, and more preferably with from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, an arylalkyl group (including substituted arylalkyl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkylaryl group (including substituted alkylaryl groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkoxy group (including linear, branched, saturated, unsaturated, cyclic, unsubstituted, and substituted alkoxy groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl portion of the alkoxy group), typically with from about 1 to about 50 carbon atoms, preferably with from about 4 to about 20 carbon atoms, and more preferably with from about 8 to about 12 carbon atoms, although the number of carbon atoms can be outside of these ranges, an aryloxy group (including substituted aryloxy groups), typically with from about 6 to about 50 carbon atoms, preferably with from about 6 to about 20 carbon atoms, and more preferably with from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, an arylalkyloxy group (including substituted arylalkyloxy groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, an alkylaryloxy group (including substituted alkylaryloxy groups), typically with from about 7 to about 50 carbon atoms, preferably with from about 7 to about 25 carbon atoms, and more preferably with from about 7 to about 15 carbon atoms, although the number of carbon atoms can be outside of these ranges, a polyalkyleneoxy group, wherein the alkyl portion of the repeat alkyleneoxy groups typically has from about 1 to about 12 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polyethyleneoxy group, a polypropyleneoxy group, a polybutyleneoxy group, or the like, and wherein the number of repeat alkyleneoxy groups typically is from about 2 to about 50 repeat alkyleneoxy groups, although the number of repeat units can be outside of these ranges, a polyaryleneoxy group, wherein the aryl portion of the repeat aryleneoxy groups typically has from about 6 to about 14 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polyphenyleneoxy group, a polynaphthaleneoxy group, a polyphenanthreneoxy group, or the like, and wherein the number of repeat aryleneoxy groups typically is from about 2 to about 20 repeat aryleneoxy groups, although the number of repeat units can be outside of these ranges, a polyarylalkyleneoxy group, wherein the arylalkyl portion of the repeat arylalkyleneoxy groups typically has from about 7 to about 50 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polybenzyleneoxy group, a polyphenylethyleneoxy group, or the like, and wherein the number of repeat arylalkyleneoxy groups typically is from about 2 to about 20 repeat arylalkyleneoxy groups, although the number of repeat units can be outside of these ranges, a polyalkylaryleneoxy group, wherein the alkylaryl portion of the repeat alkylaryleneoxy groups typically has from about 7 to about 50 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as a polytolueneoxy group or the like, and wherein the number of repeat alkylaryleneoxy groups typically is from about 2 to about 20 repeat alkylaryleneoxy groups, although the number of repeat units can be outside of these ranges, a heterocyclic group (including unsubstituted and substituted heterocyclic groups), typically with from about 2 to about 12 carbon atoms, and typically with from about 4 to about 18 ring atoms, although the number of carbon atoms and the number of ring atoms can be outside of these ranges, wherein the heteroatoms in the heterocyclic groups can be (but are not limited to) nitrogen, oxygen, sulfur, silicon, phosphorus, and the like, as well as mixtures thereof, a silyl group (including unsubstituted and substituted silyl groups), a siloxane group (including unsubstituted and substituted siloxane groups), a polysilylene group (including unsubstituted and substituted polysilylene groups), typically with from 2 to about 100 repeat silylene units, or a polysiloxane group (including unsubstituted and substituted polysiloxane groups), typically with from 2 to about 200 repeat siloxane units, although the number of repeat siloxane units can be outside of this range, wherein the substituents on the substituted alkyl, aryl, arylalkyl, alkylaryl, alkoxy, aryloxy, arylalkyloxy, alkylaryloxy, polyalkyleneoxy, polyaryleneoxy, polyarylalkyleneoxy, polyalkylaryleneoxy, heterocyclic, silyl, siloxy, polysilylene, and polysiloxy groups are hydroxy groups, halogen atoms, cyano groups, ether groups, aldehyde groups, ketone groups, carboxylic acid groups, ester groups, amide groups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups, sulfoxide groups, phosphate groups, nitrile groups, mercapto groups, nitro groups, nitroso groups, sulfone groups, acyl groups, acid anhydride groups, azide groups, cyanato groups, isocyanato groups, thiocyanato groups, isothiocyanato groups, mixtures thereof, and the like, wherein the substituents on the silylene, siloxy, polysilylene, and polysiloxy groups can also be alkyl groups, aryl groups, arylalkyl groups, and alkylaryl groups, wherein two or more substituents can be joined together to form a ring. Up to 4 Z groups can be present on the molecule.
Two or more of the groups R1, Z, and X can be joined together to form a ring.
Some specific examples of colorants of this formula include 
wherein z is an integer of from about 34 to about 44, and the like.
The compounds of the present invention can be prepared by any desired or effective method. For example, they can be prepared by diazotization of the correspondingly substituted aniline with nitrosylsulfuric acid under cold temperature conditions followed by coupling with the correspondingly substituted pyridone in a buffered alkaline aqueous solution under cold temperature conditions, as follows: 
More specifically, the correspondingly substituted aniline is first subjected to a diazotization reaction by dissolving it in acetic acid diluted with a solvent and, optionally, a second acid, such as sulfuric acid, dodecylbenzene sulfonic acid, propionic acid, hydrochloric acid, phosphoric acid, any other acid useful for a diazotization reaction, or the like, as well as mixtures thereof. The solvent can be any solvent useful in a diazotization reaction, such as water, acetone, dimethylformamide, dimethyacetamide, tetrahydrofuran, dimethoxyethane, analogous higher-boiling ether solvents, and the like, as well as mixtures thereof.
The solvent and the aniline are present in any desired or effective relative amounts; if, for purposes of determining relative amounts, xe2x80x9csolventxe2x80x9d is defined to include whatever solvent has been selected plus any amount of acetic acid and second acid present, the reactants are present in this combined solvent in relative amounts of in one embodiment at least about 100 grams of substituted aniline per liter of solvent, in another embodiment at least about 200 grams of substituted aniline per liter of solvent, and in yet another embodiment at least about 230 grams of substituted aniline per liter of solvent, and in one embodiment of no more than about 400 grams of substituted aniline per liter of solvent, in another embodiment of no more than about 300 grams of substituted aniline per liter of solvent, and in yet another embodiment of no more than about 270 grams of substituted aniline per liter of solvent, although the relative amounts can be outside of these ranges.
The acetic acid is present in any desired or effective amount, in one embodiment at least about 1 gram of acetic acid per gram of substituted aniline, in another embodiment at least about 2 grams of acetic acid per gram of substituted aniline, and in yet another embodiment at least about 3 grams of acetic acid per gram of substituted aniline, and in one embodiment no more than about 10 grams of acetic acid per gram of substituted aniline, in another embodiment no more than about 7 grams of acetic acid per gram of substituted aniline, and in yet another embodiment no more than about 5 grams of acetic acid per gram of substituted aniline, although the relative amounts can be outside of these ranges.
When present, the optional second acid is present in any desired or effective amount, in one embodiment at least about 0.05 gram of acid per gram of substituted aniline, and in another embodiment at least about 0.1 gram of acid per gram of substituted aniline, and in one embodiment no more than about 0.5 grams of acid per gram of substituted aniline, in another embodiment no more than about 0.3 grams of acid per gram of substituted aniline, and in yet another embodiment no more than about 0.2 grams of acid per gram of substituted aniline, although the relative amounts can be outside of these ranges.
Upon complete dissolution of the ingredients, the mixture is cooled, in one embodiment to a temperature of no more than about +15xc2x0 C., in another embodiment to a temperature of no more than about +10xc2x0 C., in yet another embodiment to a temperature of no more than about +5xc2x0 C., in still another embodiment to a temperature of no more than about +3xc2x0 C., and in one embodiment to a temperature of no lower than about xe2x88x925xc2x0 C., and in another embodiment to a temperature of no lower than about xe2x88x9210xc2x0 C., although the temperature can be outside of these ranges.
Thereafter, nitrosylsulfuric acid is added to the mixture in any desired or effective amount, in one embodiment at least about 1 mole of nitrosylsulfuric acid per mole of substituted aniline, and in another embodiment at least about 1.05 moles of nitrosylsulfuric acid per mole of substituted aniline, and in one embodiment no more than about 1.5 moles of nitrosylsulfuric acid per mole of substituted aniline, in another embodiment no more than about 1.25 moles of nitrosylsulfuric acid per mole of substituted aniline, and in yet another embodiment no more than about 1.1 moles of nitrosylsulfuric acid per mole of substituted aniline, although the relative amounts can be outside of these ranges. In a specific embodiment, the nitrosylsulfuric acid is added dropwise at a rate such that the temperature of the reaction mixture does not exceed 15xc2x0 C.
The reaction is essentially instantaneous, and upon completion of addition of the nitrosylsulfuric acid the reaction is essentially complete, although, if desired, a qualitative test can be performed to confirm reaction completion.
Thereafter, residual excess nitrosylsulfuric acid present in the reaction mixture can be quenched by the addition of a quenching agent, such as sulfamic acid, urea, or the like as well as mixtures thereof, in any desired or effective amount, in one embodiment at least about 0.01 mole of quenching agent per mole of nitrosylsulfuric acid (i.e., per mole of nitrosylsulfuric acid originally added to the reaction mixture), in another embodiment at least about 0.05 mole of quenching agent per mole of nitrosylsulfuric acid, and in yet another embodiment at least about 0.1 mole of quenching agent per mole of nitrosylsulfuric acid, and in one embodiment no more than about 0.5 mole of quenching agent per mole of nitrosylsulfuric acid, in another embodiment no more than about 0.3 mole of quenching agent per mole of nitrosylsulfuric acid, and in yet another embodiment no more than about 0.2 mole of quenching agent per mole of nitrosylsulfuric acid, although the amount can be outside of these ranges. Upon completion of the reaction, the reaction mixture contains the corresponding diazonium salt.
A precursor solution of the pyridone having the desired substituents thereon is prepared in an appropriate solvent, such as a mixture of water, organic solvents, including lower alcohols such as methanol, ethanol, isopropanol, and the like, water-miscible nonbasic organic solvents such as tetrahydrofuran, acetone, dimethoxyethane, N,N-dimethylformamide, N,N-dimethylacetamide, and the like, as well as mixtures thereof. Mixtures of water with an organic solvent can be helpful for ease of solvating inorganic or organic salts that are a reaction by-product. In this instance, water and the organic solvent are present in any desired or effective relative amounts, in one embodiment at least about 0.25 gram of organic solvent per gram of water, in another embodiment at least about 0.3 gram of organic solvent per gram of water, and in yet another embodiment at least about 0.4 gram of organic solvent per gram of water, and in one embodiment no more than about 4 grams of organic solvent per gram of water, in another embodiment no more than about 3 grams of organic solvent per gram of water, and in yet another embodiment no more than about 2 grams of organic solvent per gram of water, although the relative amounts can be outside of these ranges.
The pyridone is present in the precursor solution in any desired or effective amount, in one embodiment at least about 10 grams of pyridone per liter of solvent, in another embodiment at least about 30 grams of pyridone per liter of solvent, and in yet another embodiment at least about 50 grams of pyridone per liter of solvent, and in one embodiment no more than about 200 grams of pyridone per liter of solvent, in another embodiment no more than about 100 grams of pyridone per liter of solvent, and in yet another embodiment no more than about 70 grams of pyridone per liter of solvent, although the relative amounts can be outside of these ranges.
The pyridone precursor solution is maintained at an alkaline pH, typically of at least about 10, and in one embodiment no more than about 14, and in another embodiment no more than about 12, although the pH can be outside of these ranges. The pyridone precursor solution can contain a mixture of a base and an optional buffering salt.
Examples of suitable bases include mineral bases, such as sodium hydroxide, potassium hydroxide, and the like, as well as water-miscible organic tertiary amines, such as triethanolamine, N,N-diethylethanolamine, and the like, as well as mixtures thereof, present in any desired or effective amount, in one embodiment at least about 1 mole of base per mole of pyridone, in another embodiment at least about 2 moles of base per mole of pyridone, in yet another embodiment at least about 3 moles of base per mole of pyridone, and in still another embodiment at least about 5 moles of base per mole of pyridone, and in one embodiment no more than about 10 moles of base per mole of pyridone, in another embodiment no more than about 7 moles of base per mole of pyridone, and in yet another embodiment no more than about 5 moles of base per mole of pyridone, although the relative amounts can be outside of these ranges.
Examples of suitable optional buffer salts include those corresponding to the principal acid solvent; for example, when the principal acid solvent is acetic acid, suitable buffers include sodium acetate, potassium acetate, sodium hydrogenphosphate, citric acid, and the like, as well as mixtures thereof. When present, the optional buffer salt is present in any desired or effective amount, in one embodiment at least about 1 mole of buffer per mole of pyridone, in another embodiment at least about 2 moles of buffer per mole of pyridone, in yet another embodiment at least about 3 moles of buffer per mole of pyridone, and in still another embodiment at least about 5 moles of buffer per mole of pyridone, and in one embodiment no more than about 10 moles of buffer per mole of pyridone, in another embodiment no more than about 7 moles of buffer per mole of pyridone, and in yet another embodiment no more than about 5 moles of buffer per mole of pyridone, although the relative amounts can be outside of these ranges. In a specific embodiment, upon dissolution of the pyridone, the thus-formed precursor pyridone solution can be filtered to remove any undissolved solids.
The solution containing the diazonium salt, maintained at a cold temperature, is then slowly added to the pyridone solution in any desired or effective relative amounts, in one embodiment at least about 1 mole of pyridone per mole of diazonium salt, in another embodiment at least about 1.05 moles of pyridone per mole of diazonium salt, and in yet another embodiment at least about 1.1 moles of pyridone per mole of diazonium salt, and in one embodiment no more than about 2 moles of pyridone per mole of diazonium salt, in another embodiment no more than about 1.5 moles of pyridone per mole of diazonium salt, and in yet another embodiment no more than about 1.25 moles of pyridone per mole of diazonium salt, although the relative amounts can be outside of these ranges, resulting in the immediate formation of a bright yellow precipitate. Thereafter, the yellow precipitate can be collected by filtration and, if desired, washed.
Precursor anilines can be prepared by any desired or effective method, such as that disclosed in, for example, xe2x80x9cThe Chemistry of Isatoic Anhydride,xe2x80x9d G. M. Coppola, Synthesis, p. 505 (1980); xe2x80x9cIsatoic Anhydride. IV. Reactions with Various Nucleophiles,xe2x80x9d R. P. Staiger et al., J. Org. Chem., Vol. 24, p. 1214 (1959); R. P. Staiger et al., J. Chem. Eng. Data B, p. 454 (1963); and U.S. Pat. No. 4,016,143; the disclosures of each of which are totally incorporated herein by reference.
Precursor pyridones can be prepared by any desired or effective method, such as that disclosed in, for example, xe2x80x9cInvestigation of the Reaction Conditions for the Synthesis of 4,6-Disubstituted-3-cyano-2-pyridones and 4-Methyl-3-cyano-6-hydroxy-2-pyridone,xe2x80x9d D. Z. Mijin et al., J. Serb. Chem. Soc., Vol. 59, No. 12, p. 959 (1994); xe2x80x9cSynthesis of Isoquinoline Alkaloids. II. The Synthesis and Reactions of 4-Methyl-3-pyridinecarboxaldehyde and Other 4-Methyl-3-substituted Pyridines, J. M. Bobbitt et al., J. Org. Chem., Vol 25, p. 560 (1960); xe2x80x9cSynthesis and Dyeing Characteristics of 5-(4-Arylazophenyl)azo-3-cyano-4-methyl-6-hydroxy-2-pyridones,xe2x80x9d J. M. Kanhere et al., Indian Journal of Textile Research, Vol. 13, p. 213 (1988); xe2x80x9cSynthesis of Some Pyridone Azo Dyes from 1-Substituted 2-Hydroxy-6-pyridone Derivatives and their Colour Assessment,xe2x80x9d C. Chen et al., Dyes and Pigments, Vol. 15, p. 69 (1991); xe2x80x9cSynthesis of 3-Cyano-6-hydroxy-5-(2-(perfluoroalkyl)phenylazo)-2-pyridones and their Application for Dye Diffusion Thermal Transfer Printing,xe2x80x9d M. Matsui et al., Bull. Chem. Soc. Jpn., 1993, Vol. 66, Iss. 6, Pp. 1790-4; xe2x80x9cSynthesis of N-alkylcyanopyridones,xe2x80x9d B. Peng et al., Faming Zhuanli Shenqing Gongkai Shuomingshu (1997), CN 1158845; xe2x80x9cSynthesis of 1-Butyl-3-cyano-4-methyl-6-hydroxypyrid-2-one,xe2x80x9d X. Kong et al., Huaxue Shiji (1998), 20(1), 58-59; xe2x80x9cRegioselective Conversion of 3-Cyano-6-hydroxy-2-pyridones into 3-Cyano-6-amino-2-pyridones,xe2x80x9d A. R. Katritzky et al., J. Heterocycl. Chem. (1995), 32(3), 1007-10; xe2x80x9cThe Synthesis of Some Hetarylazopyridone Dyes and Solvent Effects on their Absorption Spectra,xe2x80x9d N. Ertan et al., Dyes Pigm. (1995), 27(4), 313-20; xe2x80x9cProcess for the Preparation of Pyridone Compounds,xe2x80x9d H. Schmid, Ger. Offen. DE 4314430 (1994); xe2x80x9cTautomerism of 4-Methyl-6-hydroxy-2-pyridone derivatives,xe2x80x9d H. Liu et al., Dalian Ligong Daxue Xuebao (1992), 32(4), 405-11; xe2x80x9cPreparation of 1-Alkyl-3-cyano-4-methyl-6-hydroxy-2-pyridone-type Mixed Azo Coupling Components,xe2x80x9d J. Prikryl et al., Czech. (1991) 8 pp. CODEN: CZXXA9 CS 273045 B1 19911220 CAN 118:256604 AN 1993:256604 CAPLUS; xe2x80x9cStructural Characteristics of Hydroxypyridone Derivatives,xe2x80x9d Q. Peng et al., Dalian Ligong Daxue Xuebao (1991), 31(3), 279-86; and xe2x80x9c6-Hydroxypyridin-2-ones,xe2x80x9d F. Schmidt, Ger. Offen. DE 2845863 (1980); the disclosures of each of which are totally incorporated herein by reference.
While not being limited to any particular theory, it is believed that the ortho-substitution structural feature of the colorant molecules of the present invention enables the formation of strong intramolecular hydrogen bonds between the azo group, the hydroxyl group, and the carbonyl group that imparts rigidity and significant photostability to the colorant under visible light conditions. It is believed that these bonds form as follows: 
It is believed that this structural feature can also impart thermal stability and chemical stability to the colorant molecule. Further, while not being limited to any particular theory, it is believed that including alkyl groups with at least about 12 carbon atoms, particularly (although not necessarily) branched alkyl groups of this type, in the colorant molecule further reduce diffusion or leaching of the colorant molecule from a medium such as a phase change ink vehicle into adjacent inks of different colors (leading to intercolor bleed), adjacent unprinted areas (leading to edge raggedness), tape adhesives (leading to edge raggedness and possible illegibility), and the like.
In addition to being suitable for use in phase change inks, the colorants of the present invention can be used in applications such as textile dying, biological dying applications that rely on high spectral strength chromophores, electronics applications, such as organic photoconductors, optical filters, and the like, color filters for liquid crystal display systems, and the like.
Specific embodiments of the invention will now be described in detail. These examples are intended to be illustrative, and the invention is not limited to the materials, conditions, or process parameters set forth in these embodiments. All parts and percentages are by weight unless otherwise indicated.